The contents of electronic mail (“e-mail”) messages may be generally encoded using one of a number of known protocols to facilitate secure message communication. The Secure Multiple Internet Mail Extensions (“S/MIME”) protocol, for example, relies on public and private encryption keys to provide confidentiality and integrity, and on a Public Key Infrastructure (PKI) to communicate information that provides authentication and authorization. Data encoded using a private key of a private key/public key pair is decoded using the corresponding public key of the pair, and data encoded using a public key of a private key/public key pair is decoded using the corresponding private key of the pair. Other known standards and protocols may be employed to facilitate secure message communication, such as Pretty Good Privacy™ (PGP) and variants of PGP such as OpenPGP, for example. PGP-based systems also utilize public and private encryption keys to provide confidentiality and integrity, although the authenticity of public keys used in the encoding of PGP messages are validated in a different manner as compared to S/MIME systems. Constructs similar to that of a “certificate” (as used in S/MIME for example) containing a public key and information on the key holder may be provided in secure message communication standards and protocols. One example of such a construct is known as a “PGP key” in PGP-based systems.
The contents of a message may be encrypted, digitally signed (“signed”) or both. Some protocols (e.g. some PGP variants) that are used to secure message data allow different security encodings to be applied to different parts of a message.
Consider a PGP message that contains signed message data in its message body, for example. Known messaging applications are typically adapted to generate an indicator, for display to a user through a user interface, that allows the user to quickly identify whether the message data in the body of the PGP message is signed and/or encrypted. However, the manner in which this indicator is typically displayed to users in known user interfaces of such messaging applications can be misleading. For example, when an indicator is associated with a message and identifies “the message” as being signed by an individual, the user typically assumes that all of the content of the message is signed by that individual even when, in fact, only message data in the message body is so signed.